// Time Complexity = O(N) - worst case one branch tree
// Space Complexity = O(N) - every recursion opens a stack frame
public List <int> BranchSums(NodeBT rootNode)
{
List <int> sums = new List <int>();
sums = calculateBranchSums(rootNode, 0, sums);
return(sums);
}
public void PrintInOrder(NodeBT rootNode)
{
if (rootNode != null)
{
PrintInOrder(rootNode.Left);
Console.WriteLine(rootNode.Value);
PrintInOrder(rootNode.Right);
}
}
// recursive insertion from list beginning with order i
public NodeBT InsertLevelOrder(int[] arr, NodeBT root, int i)
{
// base case for recursion
if (i < arr.Length)
{
NodeBT tempNode = new NodeBT(arr[i]);
root = tempNode;
// insert left child
root.Left = InsertLevelOrder(arr, root.Left, 2 * i + 1);
// insert right child
root.Right = InsertLevelOrder(arr, root.Right, 2 * i + 2);
}
return(root);
}
private List <int> calculateBranchSums(NodeBT node, int runningSum, List <int> sums)
{
if (node == null)
{
return(sums);
}
int newRunningSum = runningSum + node.Value;
if (node.Left == null && node.Right == null)
{
sums.Add(newRunningSum);
return(sums);
}
calculateBranchSums(node.Left, newRunningSum, sums);
calculateBranchSums(node.Right, newRunningSum, sums);
return(sums);
}
public NodeBT(int data)
{
Value = data;
Left = null;
Right = null;
}
